An apparatus for determining vehicle's entry into a parking lot and vehicle's exit from the parking lot is known. For example, Patent Document 1 (JP-2004-184089A) discloses the following technique. When an acceleration change detected with an acceleration sensor exceeds a predetermined value, it is estimated that a vehicle has crossed over a roadside ditch. Based on an estimation result, it is determined whether or not the vehicle is on a road or outside the road.
Patent Document 2 (JP-2002-333334A corresponding to US 2002/0169552A) discloses a technique for determining entry into and exit from a parking lot by taking together a vehicle speed of the vehicle, a presence or absence of turning movement, an error in a vehicle longitudinal direction estimated by map matching, a presence or absence of front or rear intersection, and a cross-road width.
The technique disclosed in Patent Document 1 uses an acceleration sensor that detects vertical direction acceleration in accordance with up and down movement of a vehicle. However, in many cases, the acceleration sensor for detecting the vertical direction acceleration is not installed in a vehicle. Cost for additional installation of this acceleration sensor is needed. Therefore, the technique disclosed in Patent Document 1 disadvantageously requires high cost.
The technique disclosed in Patent Document 2 uses a map matching process of an in-vehicle navigation apparatus, and an intersection data or a road width data handled by the in-vehicle navigation apparatus. Thus, the in-vehicle navigation apparatus should be equipped in a vehicle. Therefore, the technique disclosed in Patent Document 2 disadvantageously requires high cost.